Automotive seat assemblies often include a rearward bench seat that can be removed to increase the cargo-carrying space within the passenger compartment. This adapts the vehicle for transporting bulky items and otherwise enhances the vehicle's utility. Such removable bench seats are found, for example, in recreational vehicles, sport utility vehicles and minivans, as well as other vehicle types where the rear bench seat is accessible from a rear hatch opening in the vehicle body.
Such multiple-purpose seating arrangements must meet the same motor vehicle safety requirements as a permanently installed seat which requires the seat to be fastened to the vehicle body structure securely so that inertia forces to which the seat might be subjected can be accommodated.
Various fastening mechanisms are known in the art for securing removable bench seats while maintaining the capability of absorbing high energy loads. Examples of removable seat assemblies with fastening mechanisms of this type may be seen by referring to U.S. Pat. Nos. 4,759,580 and 4,971,379, each of which discloses a latching mechanism for securing a removable bench seat to the floor pan structure of a motor vehicle. The floor pan structure is provided with seat-anchoring pins which are situated below the surface of the passenger compartment floor and engaged by robust latching devices when the seat is moved by the user into its installed position.
Typically, the latching mechanism comprises a rotatable lever located on each lateral side of the bench seat for pivoting a latching member into a position for engaging an anchor pin. Such arrangements require considerable effort on the part of the user when he or she undertakes the task of removing a seat to enlarge the passenger compartment for carrying cargo.
U.S. Pat. No. 5,372,398 discloses a removable bench seat assembly for an automotive vehicle wherein provision is made for facilitating removal of the bench seat by providing rollers carried on seat pedestals or risers that form a part of the structural frame of the bench seat. As in the case of the earlier designs of the '580 patent and the '379 patent, provision is made in the design of the '398 patent for latching the seat to anchor posts or pins located below the surface of the floor pan. The latching mechanism includes in addition, a rotatable lever at each lateral side of the bench seat. As the lever is rotated by the user, the rollers engage a seat track which raises the seat frame above the plane of the anchor pin. The rotatable lever is connected to latching devices at fore-and-aft locations by a motion transmitting linkage. Thus, when the anchor pins are disengaged, the rollers are capable of supporting the weight of the bench seat, thereby permitting the user to roll the bench seat rearwardly through the rear hatch opening with minimal effort.
The latching mechanism and the roller assembly of the design of the '398 patent has a large number of parts. Because of the complexity of the linkage devices associated with the latches, considerable user skill is required in the manual operation of the rotatable levers at each side of the seat assembly as the user attempts to remove the seat. The design of the '398 patent further requires movable latching elements at both the fore-and-aft locations which are connected together for simultaneous movement by an articulated linkage. Other prior art devices, such as the latch system shown in U.S. Pat. No. 5,482,345, include similar fore-and-aft movable latching mechanisms, but these are independently operable as distinct from the articulated mechanism of the design of the '398 patent.